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Paul wanted to charge his 18650 (~1 years old) in his WF-139 charger over night. He almost lost his finger .... His flashlight exploded in his hand. Shows the dangerous side of li-ion batteries. The result:

Last edited by aurum; 06-29-2010 at 04:53 PM.

The Kinks - Death Of A Clown / Smokie - Living Next Door to Alice / Simon & Garfunkel - El Condor Pasa

Re: Ultrafire 18650 3000mA exploded

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I hope Paul recovers OK ....... sorry paul .

Quote : v
Paul wanted to charge his 18650 (~1 years old) in his WF-139 charger over night. He almost lost his finger .... His flashlight exploded in his hand. Shows the dangerous side of li-ion batteries. The result:
:End Quote

I am unclear .. you mention Paul wanted to charge his 18650 overnite . But you don't mention if he did infact charge it .

Looks like just the end cap blew off , but we don't know if this happened before or after the cell was charged , if the cell was Over-charged just before use , or if the light was turned on or off when it blew ? Did the thermal runaway start just before the cell was inserted maybe ?
Did he maybe DROP and damage the cell just before insertion ?

Could you please further translate for us if any more details were given as to the procedure Paul followed and what may have caused this event ?

Your Link to the DealExtreme cells shows that THEY WERE NOT PROTECTED CELLS .

Re: Ultrafire 18650 3000mA exploded

WOW, I hope you get well soon. That is one hell of a dent in that bowl. I know you got hurt mate but it could of been so much worse, it does'nt bare thinking about really . I have one of those cells, which I got given and put it away and not used it yet. Dont plan to use it now either. I think it really does pay to buy some good quality cells and be done with it. I know there is a risk with any Li-ion cell, but it should be vastly reduced by buying quality rather than xxxfire

Re: Ultrafire 18650 3000mA exploded

He charged two cells overnight, then charged the third cell the next day. When all three cells were fully charged he put them in the light and turned it on. It exploded almost immediately.

That is correct ...

I wish Paul had tested those charged cells with a volt meter to see if they got overcharged ?

I think he owns the old version of the charger (this version overcharges unprotected cells). But his cells are the protected version ... He did no test. One (or even more cells) were damaged. His wife noticed something strange the day before. The output of the flashlight was less compared to the days before.

Re: Ultrafire 18650 3000mA exploded

That is appalling!

I'm SO glad he wasn't seriously hurt.

A very frightening tale indeed.

It often strikes me that we all love to have an abundance of lights, naturally since it is our passion, and that we stockpile batteries to keep them running. Having torches and no batts would be pointless after all. But I have far more Lithium Ion batts than I am ever likely to use, Protected 14500, 17670, 18650 and RCR123A and RCR2 types, not to mention the non protected RCR123A, 14250 and 10180 types. I wear a Raw SS around my neck the whole day every day. I would hate for something like that to happen to me or to one of my children borrowing a torch!

Multi cell Lithium ion lights scare the bejasuz out of me to be frank. Since safety is dependant on the wherewithall of the user, I think I shall be retiring a lot of my 'extreme' torches to somebody with more of a need for them.

I may also take off any waterproofing gaskets and O-rings as well, I hardly ever go out in the rain at night.

Re: Ultrafire 18650 3000mA exploded

Someone please explain how this can happen with protected cells ?

Unless the XXXXFIRE cells were faulty , poor quallity control or mis-branded ?

I own the same charger (I don't use it any longer) and I ones noticed that the WF-139 still charges the cell even if the LED turns to green. Charging unprotected cells is dangerous with this charger. Second thing I noticed is that the UF 3000mA have a low internal resistance compared to other 18650 ... So it is easier to overdischarge the cells.

I think the PCB of one cell was damaged ... Due to the fact that he has charged the cells the hole night the cells where maybe 4.5V and that's it

The Kinks - Death Of A Clown / Smokie - Living Next Door to Alice / Simon & Garfunkel - El Condor Pasa

Re: Ultrafire 18650 3000mA exploded

I think they may be pushing the envelope of safety trying to put 3000mA capacity in there where other brands limit it to 2400 or 2600mA.

Nope. It's just a marketing lie. These batteries don't come close to 3000mA. They are about 2500-2600 tops.

The only companies currently capable of producing cells higher capacity then 2600mAH are Sanyo, Panasonic, Sony, LG, Samsung etc.

My guess is that the guy had unbalanced cells and mixed a junk cell with two fresh ones or something. Then there was too much stress on the junk cell and it exploded.

Also keep in mind that these cells may have not been protected, or protected very well. I find that most cells from DX and stuff that are listed as protected hardly due anything to protect the cell from overcharging or over discharging. Even several AWís that Iíve tested fail to protect the cell from being over discharged. Iíve taken an AW purposely down to 2.3v without the low voltage protection kicking in.

Lastly, if you review several of these Li-ion explosions on CPF you will find that most of them have a few things in common.

1) Multiple cells in one light2) High current draw

If your cells are used in either of these applications please make sure you test each cell indivdually to make sure all cells can deliver the same current and capacity.

Re: Ultrafire 18650 3000mA exploded

Possibly the worst 18650 to chose for a multi battery set up Im sorry to say .
The internal resistance on these is possibly the highest of any 18650 on the market .

And an important warning for anyone running a multi Li-ion set up is to check the charge state of the batteries , as often one battery discharges faster than the other . So it might be an idea to number the batteries so you can periodically swap them from front to back , to give them more even discharge .

So I guess with ever increasing numbers of 2x18650 lights on the market , we may see the 18650 doing the CR123A

The 18650 was inherently safer as it replaced the dual battery set up , with a single battery set up , so remember , any multi li-ion set up needs to be carefully monitored for voltage parity in the batteries or you may very well run the risk of turning your flashlight into a hand grenade .

Re: Ultrafire 18650 3000mA exploded

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Protected cells are NOT supposed to do this thermal runaway thing !
NOW I'm Really wondering what caused this incident !
Someone please explain how this can happen with protected cells ?

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What jirik_cz said, the battery is capable of becomming unsealed, when unsealed the anode disconnect would not function as it requires pressure to function. is ONE possibility.
other possibility with the ultrafires i own are the protection itself Shorting out, which can happen on any protected battery, but as we have seen many times the UF is not very carefull about its assembly of the whole battery package, and parts used to do so, so shorting of the protection connections is slightly more likly.

again it could happen to any of them, it was just more likly to happen with this than anything, because of its obvious flaws.